src/hwtime.h

   1 /*
   2 ** 2008 May 27
   3 **
   4 ** The author disclaims copyright to this source code.  In place of
   5 ** a legal notice, here is a blessing:
   6 **
   7 **    May you do good and not evil.
   8 **    May you find forgiveness for yourself and forgive others.
   9 **    May you share freely, never taking more than you give.
  10 **
  11 ******************************************************************************
  12 **
  13 ** This file contains inline asm code for retrieving "high-performance"
  14 ** counters for x86 class CPUs.
  15 */
  16 #ifndef SQLITE_HWTIME_H
  17 #define SQLITE_HWTIME_H
  18
  19 /*
  20 ** The following routine only works on pentium-class (or newer) processors.
  21 ** It uses the RDTSC opcode to read the cycle count value out of the
  22 ** processor and returns that value.  This can be used for high-res
  23 ** profiling.
  24 */
  25 #if (defined(__GNUC__) || defined(_MSC_VER)) && \
  26       (defined(i386) || defined(__i386__) || defined(_M_IX86))
  27
  28   #if defined(__GNUC__)
  29
  30   __inline__ sqlite_uint64 sqlite3Hwtime(void){
  31      unsigned int lo, hi;
  32      __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
  33      return (sqlite_uint64)hi << 32 | lo;
  34   }
  35
  36   #elif defined(_MSC_VER)
  37
  38   __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){
  39      __asm {
  40         rdtsc
  41         ret       ; return value at EDX:EAX
  42      }
  43   }
  44
  45   #endif
  46
  47 #elif (defined(__GNUC__) && defined(__x86_64__))
  48
  49   __inline__ sqlite_uint64 sqlite3Hwtime(void){
  50       unsigned long val;
  51       __asm__ __volatile__ ("rdtsc" : "=A" (val));
  52       return val;
  53   }
  54
  55 #elif (defined(__GNUC__) && defined(__ppc__))
  56
  57   __inline__ sqlite_uint64 sqlite3Hwtime(void){
  58       unsigned long long retval;
  59       unsigned long junk;
  60       __asm__ __volatile__ ("\n\
  61           1:      mftbu   %1\n\
  62                   mftb    %L0\n\
  63                   mftbu   %0\n\
  64                   cmpw    %0,%1\n\
  65                   bne     1b"
  66                   : "=r" (retval), "=r" (junk));
  67       return retval;
  68   }
  69
  70 #else
  71
  72   #error Need implementation of sqlite3Hwtime() for your platform.
  73
  74   /*
  75   ** To compile without implementing sqlite3Hwtime() for your platform,
  76   ** you can remove the above #error and use the following
  77   ** stub function.  You will lose timing support for many
  78   ** of the debugging and testing utilities, but it should at
  79   ** least compile and run.
  80   */
  81   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }
  82
  83 #endif
  84
  85 #endif /* !defined(SQLITE_HWTIME_H) */